freebsd-skq/sys/sys/uio.h
jhb cf15cbb1b6 - Add two new system calls: preadv() and pwritev() which are like readv()
and writev() except that they take an additional offset argument and do
  not change the current file position.  In SAT speak:
  preadv:readv::pread:read and pwritev:writev::pwrite:write.
- Try to reduce code duplication some by merging most of the old
  kern_foov() and dofilefoo() functions into new dofilefoo() functions
  that are called by kern_foov() and kern_pfoov().  The non-v functions
  now all generate a simple uio on the stack from the passed in arguments
  and then call kern_foov().  For example, read() now just builds a uio and
  calls kern_readv() and pwrite() just builds a uio and calls kern_pwritev().

PR:		kern/80362
Submitted by:	Marc Olzheim marcolz at stack dot nl (1)
Approved by:	re (scottl)
MFC after:	1 week
2005-07-07 18:17:55 +00:00

116 lines
3.8 KiB
C

/*-
* Copyright (c) 1982, 1986, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)uio.h 8.5 (Berkeley) 2/22/94
* $FreeBSD$
*/
#ifndef _SYS_UIO_H_
#define _SYS_UIO_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
#include <sys/_iovec.h>
#ifndef _SSIZE_T_DECLARED
typedef __ssize_t ssize_t;
#define _SSIZE_T_DECLARED
#endif
#ifndef _OFF_T_DECLARED
typedef __off_t off_t;
#define _OFF_T_DECLARED
#endif
#if __BSD_VISIBLE
enum uio_rw { UIO_READ, UIO_WRITE };
/* Segment flag values. */
enum uio_seg {
UIO_USERSPACE, /* from user data space */
UIO_SYSSPACE, /* from system space */
UIO_NOCOPY /* don't copy, already in object */
};
#endif
#ifdef _KERNEL
struct uio {
struct iovec *uio_iov;
int uio_iovcnt;
off_t uio_offset;
int uio_resid;
enum uio_seg uio_segflg;
enum uio_rw uio_rw;
struct thread *uio_td;
};
/*
* Limits
*
* N.B.: UIO_MAXIOV must be no less than IOV_MAX from <sys/syslimits.h>
* which in turn must be no less than _XOPEN_IOV_MAX from <limits.h>. If
* we ever make this tunable (probably pointless), then IOV_MAX should be
* removed from <sys/syslimits.h> and applications would be expected to use
* sysconf(3) to find out the correct value, or else assume the worst
* (_XOPEN_IOV_MAX). Perhaps UIO_MAXIOV should be simply defined as
* IOV_MAX.
*/
#define UIO_MAXIOV 1024 /* max 1K of iov's */
struct vm_object;
struct vm_page;
struct uio *cloneuio(struct uio *uiop);
int copyinfrom(const void * __restrict src, void * __restrict dst,
size_t len, int seg);
int copyiniov(struct iovec *iovp, u_int iovcnt, struct iovec **iov,
int error);
int copyinstrfrom(const void * __restrict src, void * __restrict dst,
size_t len, size_t * __restrict copied, int seg);
int copyinuio(struct iovec *iovp, u_int iovcnt, struct uio **uiop);
void uio_yield(void);
int uiomove(void *cp, int n, struct uio *uio);
int uiomove_frombuf(void *buf, int buflen, struct uio *uio);
int uiomove_fromphys(struct vm_page *ma[], vm_offset_t offset, int n,
struct uio *uio);
int uiomoveco(void *cp, int n, struct uio *uio, int disposable);
#else /* !_KERNEL */
__BEGIN_DECLS
ssize_t readv(int, const struct iovec *, int);
ssize_t writev(int, const struct iovec *, int);
ssize_t preadv(int, const struct iovec *, int, off_t);
ssize_t pwritev(int, const struct iovec *, int, off_t);
__END_DECLS
#endif /* _KERNEL */
#endif /* !_SYS_UIO_H_ */